JPH0552231B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Background of the Invention The present invention relates to a sewing machine, and particularly to a thread cutter for a sewing machine.

Some prior art includes threads that can be mounted on conventional sewing machines to facilitate cutting threads extending from a workpiece without the need for the sewing machine operator to deploy scissors or other thread cutters. The cutter is disclosed. Such a device is disclosed in U.S. Patent No. 2,867,184.
No., Italian Patent No. 642111 and Japanese Utility Model Registration Application No. 17470, respectively.
The first two of these devices are configured to be attached by thumb setscrews on the presser foot, and the one in the Japanese Utility Model Application is configured to connect to the sewing machine faceplate above the sewing machine needle.

Additionally, Mathews U.S. Patent No. 1195834 states:
A thread cutting blade having a protrusion extending through a slot formed in a slide plate of a sewing machine bed, the protrusion deflecting the thread being pulled below it and guiding it into the slot and onto the cutting edge of the thread cutting blade. Disclosed are those used to guide. However, because it is placed on the bed adjacent to the seam forming point, it somewhat impedes the advancement of the workpiece across the bed. In addition, short thread ends are formed that may cause the sewing machine needle to slip out.
Kuhar, U.S. Pat. No. 2,781,012, discloses a thread cutting slot cut into the bushing of the presser bar below the head of the sewing machine. However, great care must be taken when cutting the slot to ensure its effectiveness in cutting sewing thread. Ideally, the thread cutter should be
It must be concealed and securely located to prevent access by anyone other than the sewing thread to prevent injury to the operator or user of the sewing machine.

Application of the Invention The above requirements are achieved in an arrangement in which the thread cutting blade is held behind a slot extending in the face plate of the sewing machine between its two adjacent side walls. A thread cutting blade is supported on the inner surface of the face plate which is sloped such that the thread cutting blade is located at a corner of the face plate and is approximately perpendicular to the thread extending through the slot. A platform is provided extending from the side continuous with the lower edge of the slot in the face plate, thereby providing a base plate on which the thread can freely slide, and the thread is directed towards the cutting edge of the thread cutting blade. A location is provided to allow easy entry into the slot. Said slot consists of an opening small enough to allow easy entry of all the threads available to all sewing machines, while preventing entry of even the smallest finger. Any convenient means may be provided to secure the thread cutting blade on said inclined surface of the face plate. In an embodiment, a support bracket shield for a sewing machine light comprises an extension extending along said sloped surface inside the face plate and pressing the thread cutting blade thereagainst. by suitable means, such as a retaining washer located on a post formed as part of the face plate and extending through the hole in said bracket shield.
Alternatively, it is held to the face plate by a swage of a post extending through the hole. The former makes it easier to replace the thread cutting blade, and the latter is employed if deemed important.

C. Description of the embodiments Referring to FIG. 1, the bed 12 and the arm 1
4 and a head end 16 extending above the bed 12 is shown. The head end 16 is closed by a continuous wall of a face plate 18, and the arm 14 and face plate 18 are covered by a top cover 20. Bed 12 supports throat plate 22 and slide plate 24 thereon in any manner well known in the sewing machine industry.

The head end 16 carries a presser bar bushing 26 which slidably supports therein a presser bar 28 terminating in a presser foot 29. As is well known in the sewing machine industry, presser foot 29 may be raised by presser bar 30 or held in a lowered position as shown.
The presser foot 29 is maintained on or against the workpiece placed between it and the throat plate 22 . A needle bar (not shown) is located in front of the presser bar 28.
is positioned, and the needle bar terminates in a sewing machine needle 32 that reciprocates to fill a hole 33 in presser foot 29 in a manner well known in the sewing machine industry.
, through the workpiece material, and through a hole (not shown) in the throat plate 22 to be forced into cooperation with the sewing mechanism located within the sewing machine bed 12 .
In FIG. 1, the lower thread or bobbin thread 34 is passed from a lower thread feeder (not shown for the sake of clarity) disposed within the bed 12 to an opening (not shown) in the presser foot 29 and a hole 33. extends through. Needle thread 35 is shown extending from its source (not shown) to eye 36 of sewing needle 32.

The bobbin thread 34 and upper thread 35 are shown extending upwardly from the sides of the face plate 18 to a platform 38 that gradually merges with the rear corner 39 of the face plate 18 (see FIG. 3). The platform 38 slopes upward toward the rear corner 39 of the face plate 18 and extends inwardly into the face plate 18 to form the slot 4.
Form the bottom of 0. Slot 40 extends from the exterior of faceplate 18 through side wall 42 and through rear wall 44 to the interior of faceplate 18. In this way,
Slot 40 extends through side walls 42 and rear wall 44 of face plate 18 on either side of rear corner 39 of face plate 18.

Referring now to FIG. 2, the interior surface of the faceplate 18 is shown in elevation, and the support bracket shield 48 is shown secured to the faceplate 18 by swaged posts 50; It is integrally formed with the faceplate 18 and extends through an opening 49 in the support bracket shield 48. A cooling vent 52 is cast or molded into the faceplate 18 above the support bracket shield 48. The support bracket shield 48 is provided with a forwardly projecting ear 54 which abuts a thread cutting blade 56 held between it and the faceplate 18. A light bulb 53, shown in dashed lines in FIG. can be dissipated.

Next, referring to FIG. 3, the line (3-
3), that is to say at the underside of the slot 40, is shown. In the figure, support bracket shield 48 is attached to face plate 1.
8, from which the pillar 50 extends from the support bracket shield 48.
The opening 49 extends through the opening 49 . Posts 50 are swaged to maintain support bracket shield 48 fixedly connected to faceplate 18. It is clear that retaining washers can be used instead of swaging. Support bracket shield 4
The ears 54 of the slots 4 rest on slopes 60 extending forward and toward the rear corners 39 of the face plate 18.
It is bent inward towards the inside of 0. The slot 40 is spaced generally from the center of the ramp 60 which is covered by the ear 54 (see also FIG. 2). The blade 56 has its cutting edge 57 at the rear corner 39.
and is held on ramp 60 by ears 54 of support bracket shield 48. In FIG. 3, the upper thread 35 and lower thread 34 are connected to the platform 3.
8 and turns at the platform 38 to slide into the slot 40 substantially at right angles to the cutting edge 57 of the blade 56. As shown in FIG. 1, this lifts the material 64 and guides the threads 34, 35 upwardly along the platform 38, while also ensuring that the ends of the threads are long enough to prevent the threads from coming off the sewing machine needle 32. This can be accomplished very easily by cutting the threads 34, 35 at a sufficient distance from the sewing machine needle 32 and needle plate 22 so as to obtain the desired length.

As mentioned above, it is a sewing machine thread cutter,
Sewing machine needle and throat plate in order to obtain a thread end of appropriate length to effectively prevent injury to the sewing machine operator, do not spoil the aesthetically pleasing appearance of the sewing machine, and prevent the thread from coming out of the sewing machine mechanism. By providing a cutting edge substantially perpendicular to the thread at a suitable distance from the thread, reliable cutting of the thread is provided.

From the above explanation made with reference to the attached drawings,
The advantages of the construction and mode of operation of the apparatus of the present invention will be readily understood by those skilled in the art. Although the present invention has been described in conjunction with what is considered to be the best mode of its operation and the principles of its operation, the illustrated device is for illustrative purposes only and as encompassed within the scope of the following claims. It should be understood that all modifications may be made as desired.

[Brief explanation of the drawing]

Fig. 1 is a rear perspective view of a part of the sewing machine embodying the present invention; Fig. 2 is an elevational view of the interior of the face plate showing the orientation of the thread cutter slot; Fig. 3 is a view showing the appearance of the thread cutter in use. 1 is a cross-sectional view taken substantially along line 3-3 of FIG. 1; FIG. In the drawing, 10 is the "sewing machine part"; 12 is the "bed"; 14 is the "arm"; 16 is the "head end";
18 is the ``face plate''; 22 is the ``throat plate''; 29 is the ``presser foot''; 32 is the ``needle bar''; 34 is the ``bobbin thread''; 35 is the ``upper thread''; 36 is the ``eye''; 40 is the ``slot''; 42 is the ``side wall''; 54
is "ear"; 44 is "rear wall"; 56 is "blade";
57 indicates a "cutting edge"; 60 indicates a "slope".

Claims (1)

[Scope of Claims] 1 A sewing machine including a head end and a face plate covering the head end, the face plate defining an interior for accommodating the head end, and a continuous sewing machine including a side wall and a rear wall. a wall; a slot that extends continuously from the outside of the face plate into the interior of the face plate through a common rear corner of the adjacent side wall and rear wall; and a slot that extends from the interior of the face plate into the slot; a blade having an extending cutting edge, whereby thread extending through the slot is cut upon impact with the cutting edge of the blade. 2. The sewing machine according to claim 1, wherein the slot is an opening that accommodates only sewing thread. 3. The sewing machine according to claim 1, further comprising a platform extending from the face plate on the outside of the side wall, the platform extending on a common plane with the bottom surface of the slot,
A sewing machine whereby the sewing thread extends to said platform as a turning point and then slides along said platform to reach said slot and the cutting edge of said thread cutting blade. 4. A face plate for a sewing machine having a head end: a continuous wall defining an interior accommodating the head end and having a side wall and a rear wall; a common rear corner of adjacent side walls and rear walls; a slot continuously existing from the outside of the face plate to the inside of the face plate through;
a blade extending from the interior of the face plate and having a cutting edge extending into the slot, whereby thread extending through the slot is cut by impacting the cutting edge of the blade; , face plate. 5 In the face plate described in claim 4:
further comprising a platform extending from the face plate on the exterior of one of the side walls and rear wall, the platform extending coplanar with the bottom surface of the slot, such that the sewing thread can reach the platform as a turning point; a face plate extending up to and then sliding along the platform to reach the slot and the cutting edge of the thread cutting blade.